Potato skins can be prepared by manually removing the potato flesh, but of course manual methods are slow and/or expensive. A machine has been described in U.S. Pat. No. 4,420,494 (published after the priority date of the present Application) in which a spray of slurry or solid particles is directed onto the exposed cut surface of a potato half so as to abrade away the central potato flesh. This machine has two disadvantages. Firstly it can only be used on potatoes which have been partially cooked so that the machine cannot produce a raw (uncooked) potato skin, and secondly the potato flesh removed (which is usually in the form of a slurry) has to be thrown away or has to be dried out before it can be used.